Lamp circuit



Nov. 3, 1942. F REDY 2,300,916

' i LAMP CIRCUIT Filed July 24, 1940' no @il 1 INVENTOR. a J0 BY: .fimz w/ Fare Patentecl Nov. 3, 1942 UNITED STATES PATENT OFFICE LAMPCIBCUIT Frank Furc y. Chicago, 111., assignor to Silll.

Kraft, Inc., Chicago, 111., a corporation lllinois Application 1.1, 24, 1g, Serial No. 341,258 i Claims. (ct l'i6---1 2i) This invention relates to a circuit for enersih ing a gaseous discharge lamp, particularly an ultra-violet lamp.

. It is an object of this invention to provide an electronic tube oscillator circuit of such aimplicity and compactness that it may be mounted in a space of restricted area, as, for example, the

base oi an ultra-violet lamp fixture, stand or in a P r able unit. a i

It is a further object of the invention taprovide a high frequency oscillating circuit capable oi energization from the ordinary house circuit withoutuse of a power transformer and which that it may be mounted within an area of small charge tube exhausted to a high vacuum, filled with mercury vapor, argon, neon, helium, and krypton or other suitable rare gases and with a globule l of mercury, aiter which the lamp is sealed oii. High frequency voltage for the excitation of the lamp is supplied thereto by external clips, terminals or electrodes i which mount the lamp in a reflector as described in my eopending application Serial. No. 347,258 flied July 24, 1940. r

A voltage is applied .to the terminals 6 through the long leads I and II which in the lamp shown in said copending application are of the order of thirty inches in length and are connected at their outer ends to the plug terminals ll fitting into the socket terminals It in the output of the 111th frequency generating or oscillating circuit it. The circuit It comprises a rectifying duo-diode thermionic vacuum tube, It coupled to a power amplifier thermionic vacuum tube It. The duodiode tube It comprises a pair of plates 22 and ll, cathodes 2t and II, heater filaments ill and 82 and a shield of which the prong N is the volume, as, for example, a space of cubic area ot the order of five inches by three inches by five inches, and at the same time supply sumcient power for the high frequency energization oi an electrodeless gaseous discharge tube.

terminal connection.

The plates 22 and 24 are connected in parallel by the wire It and by a wire it to the timing switch ll of a conventional timing mechamsm,

preferably a clock mechanism embodying the Anotherobject of the, invention is to provide a simple high or radio frequency oscillating supply circuit foractivating an ultra-violet ray gaseous discharge tube and simultaneously pro-,

ducing ozone. J

Other and further objects and advantages the invention will be apparent from the following description when taken in connection with the accompanying drawing, wherein:

switch 40. The other terminal ofthe timing switch ll is connected to one of the supply lines as the line L-I by the wire 42. I

The tube 2| comprises a plate or anode M, a screen grid 46, a control grid ll, a cathode II, a heater filament iii, and a shield of which the prong 54 is the terminal connection. r

The heater filaments 30 and 81 of the tube It and the filament i! of the tube 2| are connected in series-with each other and with the ballast Figure 1 is a schematic drawing of a circuit in accordance with the invention for energization by alternating or direct current;

Figure 2 is a schematic drawing of a circuit in accordance with the invention for energization by alternating current only;

Figure 3. is aschematic drawing of a modification of the circuit of Figure 1; and

resistorgtt oia ballast tube 58, The "circuit to the heater filaments extends from the line L-l through the wire 42, the timing switch ll,v the Figure 4 is a schematic drawing showing how the circuit of Figures 1 to 3 maybe addedto for selectively operatins a quartz ultra-violet lamp I as a hot quartz lamp or a cold quartz lamp.

As shown in Figure 1, the lamp 2, which may be a quartz ultra-violet ray lamp or a fluorescent lamp, comprises an,electrodeless gaseous disfor the tubes II and II.

wire 38, the wire 36, the wire it, the ballast resistor 56, the wire 82, the heater filaments ll and 32, the wire it, the heater filament 52, the wire 66 and the wire 68 to the supply line 14-4. The lines L-l and L-2 represent the standard house circuit oi volts. The tubes II and 2| are of types which require a heater voltage of 25 volts andthe ballast resistor 58 is accordingly designed to cause a voltage drop of sixty volts at the rated current value of the heater currents The cathodes 2t and 28 of the tube II- are connected together by the wires ",1! and II and to the screen grid it of the tube II by the wire 14. The cathodes 28 and 28 are also connected by the wire 18 to one side of a condenser '18, the other side of which is connected by the wire 88 to the return wire 88. The shield prong 34 or the tube I8 is connected by the wire 82 to the heater filament 82 of the tube 28 and the lead 88 from the return wire 88.

The cathode 88 of the tube 28 is connected by the wire 84 and the wire 82 to the heater filament 82 and the lead 88 to the return wire 88. The shield prong 54 is similarly connected by the wire 88 leading to the wire 82.

The control grid 48 is coupled to the cathode 58 by a wire 88 in which is interposed'a grid resistor 88, the wire 88 being connected to the wire 88 and by the wires 82 and 84 to the cathode 58. The plate or anode 44 of the tube 28 is connected by a wire 82 to an intermediate tap 84' of an air core induction coil or inductance 98. The" control grid 48 is coupled to the end 88 of the induction coil 88 through a condenser I88 interposed in a wire I82 connected at one end to the control grid and at the other end to the end 88 of the induction coil.

A tap I84 of the induction coil intermediate the end 88 and the tap 84 is connected by the wire I88 to the common wire 18 for the cathodes 28 and 28 of the tube I8 and to the condenser I8. The terminals of the output socket I4 are connected by the wires I88 and I I 8 to the, end 98 and the tap 84 respectively of the induction coil 98.

The end II2 of the induction coil 88 is coupled to the end 88 of the induction coil by the wire I I4 and the wire I88.

In a preferred construction the tube I8 is a 25Z6G high vacuum rectifier tube and the tube 28 a 25L6G power amplifier tube. In this pre- The circuit shown in Figure l operates either on alternating current or direct current. In the case of direct current the wire 42 must of course be connected to the positive supply line. In Figure 2 there is shown a full wave rectifier and voltage doubling circuit in which the plate 22 and the cathode 28 are connected by wires H8 and H8 to the series condensers I28 and I22 to the common tap I24 of which the return line 88 to the line L2 is connected. The cathode 28 is connected in parallel to the plate 24 which is connected by the wire I28 and through the timing switch 48 to the supply line LI.

The tap I84 of the induction coil is connected by the wire I38 to the wire II8 extending between the condenser I22 and the cathode 28 of the duo-diode tube I8. It should be observed that in the circuit of Figure 2, the cathode 88 and shield prong 54 of the tube 28 are not connected to the heater filament 82 of this tube,

' but that the wire 82 connecting the shield prong ferred construction, the circuit constants have the following value:

1. The ballast resistor 56-208 ohms;

2. The grid resistor, Bil-40,000 ohms;

3. The grid condenser, 100-.08025 microfarads;

4. The condenser I8 is an electrolytic 450 volt condenser with a value of four microfarads;

5. The induction coil 88 is of number 28 octton and enamel magnet wire of 7 2 turns wound on a inch tube; and the tap I84 is located at three turns from the end 88 oi the induction coil and the tap 84 located at three turns from the tap I84.

In operation, the duo-diode thermionic tube operates as a half wave rectifier, passing current when the line LI is positive from the wires 38 and 38-through the plates 22 and 24, the cathodes 28 and 28, the wires 88, I8 and I2, the wire 18, the wire I88, the tap I84, three turns of the induction coil 88, the tap 84, and the wire 82, to the plate or anode 44 of the tube 28. The current passes from the plate or anode 44 through the cathode 58 and by the wires 84, 82, 88 and 68 to the negative lead L--2.

As the charges build up on the condenser I 88 and then leak away, a high frequency current is produced in the induction coil 88 ata frequency with the given constants of approximately 550 kilocycles, suflicient to excite the lamp 2 to luminescence, but the visible rays within the lamp tube do not extend completely from end to end of the tube and a slight flickering is observed. The

portion of the induction coil 88 between the tap 84 and the end II2 when connected as shown reeniorces the current from the portion of the coil between the taps 88, I84 and 84, and causes the rays to extend completely from end to end of the lamp tube 2 and with a steady glow.

34 of the tube I8 to the cathode 58 and shield prong 54 of the tube 28 is connected by the wire I3I to the wire I I8 extending between the condenser l28 and the plate or anode 22 of the tube I8.

Where desired, the tube 2 may be mounted in close proximity to the coil 98 and be energized thereby without electrical connection to the coil. The circuit of Figure 2 is otherwise the same as the circuit of Figure 1. The circuit shown in Figure 2 has the advantage over the circuit shown in Figure l of greaterpower, but the disadvantage that it can only be used with alternating current.

ballast tube 88, the other side of the resistor being connected by the wire I42 to the plate lead I88. The shield prong I 44 is connected to the wire 82 of the circuit shown in Figure 1 and the power line L2 is connected to the return line 88 of the circuit of Figure 1.

In the circuit shown in Fig. 4, the lamp tube 2 is heated by coils I88 and I48 of number 28 nichrome wire snugly embracing the quartz en- 'velope of the lamp tube. Current is supplied to these heating coils I46 and I48 through the timing switch 48 from the line LI through the wire I88, a manually operable switch I82, a wire I54, the wires I88 and I88 in parallel, the heater coils I48 and I48 in parallel, the wires I88 and I82and the wire I84 to the supply line L2. Upon closing of the switch I52 the circuit to the heating coils I48 and I48 is completed and the lamp operates as a hot qu'artz lamp supplying rays of radiant energy of the order of 2800 Angstrom units, but with the switch I52 in open circuit position, the lamp operates as a cold quartz lamp supplying rays of radiant energy of pure ultra violet or the order of 2537 Angstrom'units.

It is obvious that various changes may be made in the specific embodiments of the invention set forth for purposes of illustration without departing from the spirit of the invention. Accordingly the invention is not to be limited to the specific embodiments shown and described but only as indicated in the following claims.

The invention is hereby claimed as follows:

1. A circuit for energizing a gaseous discharge tube, comprising a thermionic tube having plate, cathode and grid electrodes, means for applying a rectified voltage across said plate and cathode, an induction coil adapted to energize said gaseous discharge tube and having an intermediate portion in the direct current plate circuit of said tube, a direct conductive connection between the opposite ends of said induction coil, and connections including capacity and resistance between the grid and cathode electrodes of said therm ionic tube and said connected ends of said induction coil. i

2. A circuit for energizing gaseous discharge tubes, comprising a thermionic tube having plate,

cathode and grid electrodes, means for applying a rectified voltage across said plate and cathode,

gaseous discharge tube, and a connection between" the connected ends of said induction coil and said gaseous discharge tube.

3. A circuit for energizing a gaseous discharge lamp comprising a.=source of alternating current, a duo-diode thermionic vacuum tube, a fullwave rectifying voltage doubling circuit including a pair of condensers havi a common connection to said source and eac connected in series'wlth one .of the diodes of id duo-diode tube, a thermionic vacuum tub electrodes and a heater filament for said cathode electrode, a common mid-tap connection between said condensers and said heater filament, an induction coil for supplying energy to said lamp and having a portioncthereof c nected to the positive potential side of one said condensers and to the plate electrodeof a connection including capacity from another id thermionic tube,

portion of said induction coil to the grid electrode, a connection including a leak impedance between the grid electrode and the cathode, and a direct conductive connection between the opposite ends of said induction coil.

4. A circuit for energizing a gaseous discharge tube comprising a thermionic tube having plate,

cathode and grid electrodes, means for applying a direct current voltage across said plate and cathode, an induction coil, a circuit connecting one end of said coil to said grid electrode, means for connecting the plate and cathode to intermediate taps on said induction coil, a capacity in the circuit between the coil and the grid, resistanceconnected between the grid and cathode electrodes, 9. direct conductive connection between the opposite ends of said induction coil, and a circuit connecting one of said coil taps and one end of said coil to said gaseous discharge tube.

5. A circuit for energizing a gaseous discharge aving grid, plate and cathode resistance from said grid to said plate and oath. ode electrodes. l

6. A circuit for energizing a gaseous discharge lamp comprising a rectifier having a pair of rectiiying electrodes, an induction coil for supplying energy to said gaseous discharge lamp, an electronic tube having plate, cathode and grid electrodes, a direct current plate circuit for said tube including in series said plate and cathode electrodes, said rectifying electrodes and a portion I of said induction coil,a condenser connected to another portion of said induction coil and to the grid electrode of said tube, and a leak impedance connecting the grid and cathode electrodes.

7. A lamp circuit comprising a cold quartz ultra-violet ray gaseous discharge lamp having spaced current electrodes, a power supply source, a high frequency oscillating circuit connected to said source and said electrodes for supplying space current to said electrodes, and a heater independent of the space current in said lamp, said heater being connected to said source and positioned to heat the quartz envelope of said lamp, thereby causing the lamp to emit. rays characteristic of a hot quartz ultra-violet ray lamp.

8. A lamp circuit comprising a cold quartz" ultra-violet ray gaseous discharge lamp having spacedcurrent electrodes and emitting rays of one wave length band, a power supply source, a high frequency oscillating circuit connected to said source and to said electrodes for supplying space current to said electrodes, a heater independent of the space current in said lamp, said, heater being connected to said source in parallel to said oscillating circuit and positioned to heat the quartz envelope of said lamp for changing the band width of the rays transmitted through the quartz envelope of the tube, thereby causing the lamp to operate with the characteristic of a hot quartz ultra-violet ray lamp, a control switch in the parallel circuit of said heater, and a time-controlled switch connected in common to said oscillating circuit and the circuit of said heater for simultaneously controlling the deenergization of both or said circuits.

9. A circuit for energizing a gaseous discharge lamp from a standard low voltage power supply source, comprising input, leads adapted to be conlamp from a standard low voltage power supply nected to said source, a rectifier having a pair of rectifying electrodes, an inductance for supplying energy to said discharge lamp, an electronic tube having plate, cathode and grid electrodes, a

circuit in which said pair of rectifying electrodes,

said inductance, and said plate and cathode electrodes are connected in series to said input leads, connections including a capacity and resistance from said grid to one of said plate and cathode electrodes and to said circuit, and a condenser connected in shunt to that portion of said circuit which consists of the plate and cathode electrodes in series with said inductance.

10. A circuit for energizing a gaseous discharge larnp, a standard low voltage power supply source, comprising input leads adapted to be connected to saidisource, a rectifier having a pair of rectifyingelectrodes, an electronic tube having plate, cathode and grid electrodes, an inductance for supplying energy to said gaseous discharge lamp, 9. first circuit including in series said pair of rectifying electrodes, said inductance and said plate and cathode electrodes and connected to said input leads, a condenser connected in shunt to that portion of said circuit which consists of the plate and cathode electrodes in series with said inductance, a second circuit including in series a resistance, a second condenser, and a second inductance, said second circuit being connected between said second condenser and resistance to said grid and at one end to said cathode electrode and at the other end to said first inductance, said second inductance being coupled to said first inductance.

11. A circuit for energizing a gaseous dis charge lamp, a standard low voltage power supply source, comprising input leads adapted to be connected to said source, a rectifier having a pair of rectifying electrodes, an electronic tube having plate, cathode, and grid electrodes, an inductance for supplying energy to said gaseous discharge lamp, 9, first circuit including in series said pair of rectifying electrodes, their inductance and said plate and cathode electrodes and connected to said input leads, a condenser connected in shunt to that portion of said circuit which consists of the plate and cathode electrodes in series with said inductance, a second circuit including in series a resistance, a second condenser, and a second inductance, said second circuit being connected between said second condenser and resistance to said grid and at one end to said cathode electrode and at the other end to one end of said first inductance, said second inductance being coupled to said first inductance, and a third inductance connected at one end to said second circuit between said second condenser and said second inductance and at the other end to the other end of said first inductance. L

12. A circuit for energizing a gaseous discharge lamp comprising a thermionic tube having plate, cathode and grid electrodes, means for applying a direct current voltage across the plate and cathode, an induction coil for supplying energy to said lamp, means for connecting the plate and cathode to intermediate taps-on said induction coil, acircuit including a capacity and a resistance in series, said circuit being connected between said capacity and resistance to said grid and at one end to the cathode and at the other end t one end or the induction coil, and a direct conductive connection between opposite ends of said coil. I

13. A circuit for energizing a gaseous discharge lamp comprising a thermionic tube having plate, cathode, and grid electrodes, a series of direct current voltage, an induction coil having a pair of intermediate taps and for supplying energy to said gaseous discharge lamp, a circuit including. in series said source, the portion or said induction coil between said intermediate taps and said plate and cathode electrodes, a condenser connected acrosss aid sourc in parallel to that portion of said circuit which consists oi plate and cathode electrodes in series with the portion of the induction coil between said intermediate taps, a second circuit including a second condenser and a resistance in series, said second circuit being connected between trig condenser and the resistance to said grid electrode and at one end to said cathode electrode and at the opposite end to one end of said induction coil. and a direct conductive connection between one end of said induction coil and the opposite end of said induction coil.

14. A circuit for energizing a gaseous discharge lamp from a standard low voltage source of power, said circuit comprising electronic means having a plate electrode, screen grid electrode, control grid electrode, and a cathode, rectifying electrodes comprising second and third plate electrodes and second and third cathodes, heaters for said three cathodes, input leads adapted to be connected to said source, the second and third plate electrodes being connected in parallel to one of said leads, the first cathode electrode being connected to the other lead, said heaters being connected in series across said leads, said cathodes having a common connection to said screen grid, an induction coil having a pair of intermediate taps, a common connection from said second and third cathodes to one of said taps, a connection from the other of said taps to the first plate electrode, a high voltage condenser connected on one side to the first cathode and on the other side connected in common to said second and third cathodes, a condenser connected between one end or said induction coil and said grid, and a resistance connected between the grid and the first cathode, and a direct conductive connection between the other end or said induction coil and said one end of said coil.

15. A circuit for energizing a gaseous discharge vapor tube, comprising a thermionic tube having plate, cathode, and grid electrodes, means for applying a direct current voltage across said plate and cathode, an induction coil for energizing saidvapor tube and having an intermediate portion in the plate circuit of said tube, a direct conductive connection between the opposite ends oi said induction coil, connections including capacity and resistance between the grid and cathode electrodes of said thermionic tube and said connected ends of said induction coil, a connection from said connected ends 01' said coil to said vapor tube, and a connection from said intermediate portion of the coil to said vapor tube.

16. A circuit for energizing a gaseous discharge vapor lamp comprising a thermionic tube having plate, cathode, and grid electrodes, means for applying a direct current voltage across the plate and cathode, an induction coil for supplying energy to said lamp, means for connecting th plate and cathode to intermediate taps on said induction coil, a circuit including a capacity and a resistance in series, said circiut being connected between the capacity and resistance to said grid and at one end to the cathode and at the other end to one end oi the induction coil, a direct, conductive connection to opposite ends of said coil, and a circuit connecting one of said taps and said connected ends of said coil to said vapor lamp.

FRANK FUREDY. 

